It has been known to use a dielectric sealing material for sealing or encapsulating a semi-conductor chip or electronic part. Generally, liquid epoxy resin has been used as the sealing material which is coated on a part followed by being cured by heat. To satisfy a demand of minimizing warp of the encapsulated or sealed part, it has been proposed to include an inorganic filler such as silica or alumina in the sealing resin, and/or to reduce elasticity of the resin in an attempt to reduce a difference in coefficient of linear thermal expansion between the resin and the part, or reduce elasticity of the resin, thereby minimizing a stress developed between the resin and the part, for example, as disclosed in and JP2004-27005 A and JP 2006-232950 A. The inorganic filler such as silica or alumina is found advantageous to lower the coefficient of linear thermal expansion as close as that of the part when incorporated in a large amount. However, as the inorganic filler is incorporated in a larger amount, there arises a problem that the inorganic filler is likely to cause more serious wear on a dicing blade or grinder which is necessarily used in a process of singulation or grinding of the device, thereby lowering manufacturability with an increased cost.